The use of wireless networks, to support mobile data communications, continues to grow rapidly. One trend in the implementation of cellular wireless networks is the increasing reliance on heterogeneous networks (HetNets). A heterogeneous cellular network may include traditional macrocell base stations overlaid with small cells (femtocells, picocells, wireless relays, etc.). The small cells may include, relative to the macrocells, smaller form factor and lower power radio nodes. By deploying HetNets with targeted small cell installations, network operators can offload users from macrocells to small cells. This technique may be particularly useful in areas with poor radio reception and/or dense mobile device populations.
eMBMS (enhanced Multimedia Broadcast Multicast Service) is a point-to-multipoint interface specification for existing and upcoming Third Generation Partnership Project (3GPP) cellular networks, which is designed to provide efficient delivery of broadcast and multicast services, both within a cell as well as over multiple cells. eMBMS services may be provided using pre-defined sub-frames, on a particular frequency band, across all the base stations in the eMBMS coverage area. A base station that does not participate in eMBMS may cause interference to the eMBMS service when it uses the eMBMS frequency band for non-eMBMS communications. Interference may reduce the signal-to-interference-plus-noise ratio (SINR) in the eMBMS coverage area. Accordingly, in 3GPP Long Term Evolution (LTE) networks, care is taken that base station in the eMBMS service area do not opt out from providing eMBMS service, so that the overall eMBMS SINR stays high.
With the advent of HetNet deployments using small cells of differing capabilities (e.g. femtocells or low power picocells), there is potential for disruption to uniform eMBMS service due to the lack of equipment feature parity, network connectivity etc. This is especially true in high density urban populations, which otherwise may be an ideal environment for deployment of broadcast services such as eMBMS as well as femtocells to increase coverage and capacity in select areas. Femtocells, however, due to relatively high latency connections with the LTE core network and/or due to other reasons such as cost considerations, may not be capable of participating in eMBMS services. Thus, when an eMBMS service is deployed in such an area, the femtocells may create “islands” where no eMBMS service can be offered and, in fact, can cause interference to the eMBMS service in the vicinity.